Playing a file in another domain works with http://www.schillmania.com/projects/soundmanager2/ or http://www.jplayer.org/ (http://jsfiddle.net/Q4LMV/18076/)
https://github.com/CreateJS/SoundJS/ instead respect same origin security policy (http://jsfiddle.net/SeUD7/) like your library.
That being said, i like your lightweight library, well done.